org.sosy_lab.solver.basicimpl.cache

Class CachingOptimizationProverEnvironment

java.lang.Object

org.sosy_lab.solver.basicimpl.cache.CachingOptimizationProverEnvironment

All Implemented Interfaces:

AutoCloseable, BasicProverEnvironment<Void>, OptimizationProverEnvironment

public class CachingOptimizationProverEnvironment
extends Object
implements OptimizationProverEnvironment

Caching wrapper for an optimizing SMT solver.

Nested Class Summary

Nested classes/interfaces inherited from interface org.sosy_lab.solver.api.OptimizationProverEnvironment

OptimizationProverEnvironment.OptStatus

Constructor Summary

Constructors

Constructor and Description
CachingOptimizationProverEnvironment(OptimizationProverEnvironment pDelegate, Map<OptimizationQuery,OptimizationResult> pCache, OptimizationCacheStatistics pStatistics)

Method Summary

Modifier and Type	Method and Description
Void	addConstraint(BooleanFormula constraint) Add constraint to the context.
OptimizationProverEnvironment.OptStatus	check() Optimize the objective function subject to the previously imposed constraints.
void	close() Closes the prover environment.
Model	getModel() Get a satisfying assignment.
ImmutableList<Model.ValueAssignment>	getModelAssignments() Get a list of satisfying assignments.
boolean	isUnsat() Check whether the conjunction of all formulas on the stack is unsatisfiable.
Optional<Rational>	lower(int handle, Rational epsilon)
int	maximize(Formula objective) Add the maximization objective.
int	minimize(Formula objective) Add minimization objective.
void	pop() Remove one formula from the environment stack.
void	push() Create backtracking point.
Void	push(BooleanFormula f) Push a backtracking point and add a formula to the environment stack, asserting it.
String	toString()
Optional<Rational>	upper(int handle, Rational epsilon)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

CachingOptimizationProverEnvironment

public CachingOptimizationProverEnvironment(OptimizationProverEnvironment pDelegate,
                                            Map<OptimizationQuery,OptimizationResult> pCache,
                                            OptimizationCacheStatistics pStatistics)

Method Detail

maximize

public int maximize(Formula objective)

Description copied from interface: OptimizationProverEnvironment

Add the maximization objective. Note: push/pop may be used for switching objectives

Specified by:

maximize in interface OptimizationProverEnvironment

Returns:

Objective handle, to be used for retrieving the value.

minimize

public int minimize(Formula objective)

Description copied from interface: OptimizationProverEnvironment

Add minimization objective. Note: push/pop may be used for switching objectives

Specified by:

minimize in interface OptimizationProverEnvironment

Returns:

Objective handle, to be used for retrieving the value.

addConstraint

@Nullable
public Void addConstraint(BooleanFormula constraint)

Description copied from interface: BasicProverEnvironment

Add constraint to the context.

Specified by:

addConstraint in interface BasicProverEnvironment<Void>

push

@Nullable
public Void push(BooleanFormula f)

Description copied from interface: BasicProverEnvironment

Push a backtracking point and add a formula to the environment stack, asserting it. The return value may be used to identify this formula later on in a query (this depends on the sub-type of the environment).

Specified by:

push in interface BasicProverEnvironment<Void>

push

public void push()

Description copied from interface: BasicProverEnvironment

Create backtracking point.

Specified by:

push in interface BasicProverEnvironment<Void>

pop

public void pop()

Description copied from interface: BasicProverEnvironment

Remove one formula from the environment stack.

Specified by:

pop in interface BasicProverEnvironment<Void>

check

public OptimizationProverEnvironment.OptStatus check()
                                              throws InterruptedException,
                                                     SolverException

Description copied from interface: OptimizationProverEnvironment

Optimize the objective function subject to the previously imposed constraints.

Specified by:

check in interface OptimizationProverEnvironment

Returns:

Status of the optimization problem.

Throws:

InterruptedException

SolverException

upper

public Optional<Rational> upper(int handle,
                                Rational epsilon)

Specified by:

upper in interface OptimizationProverEnvironment

epsilon - Value to substitute for the epsilon.

Returns:

Upper approximation of the optimized value, or absent optional if the objective is unbounded.

lower

public Optional<Rational> lower(int handle,
                                Rational epsilon)

Specified by:

lower in interface OptimizationProverEnvironment

epsilon - Value to substitute for the epsilon.

Returns:

Lower approximation of the optimized value, or absent optional if the objective is unbounded.

isUnsat

public boolean isUnsat()
                throws SolverException,
                       InterruptedException

Description copied from interface: BasicProverEnvironment

Check whether the conjunction of all formulas on the stack is unsatisfiable.

Specified by:

isUnsat in interface BasicProverEnvironment<Void>

Throws:

SolverException

InterruptedException

getModel

public Model getModel()
               throws SolverException

Description copied from interface: BasicProverEnvironment

Get a satisfying assignment. This should be called only immediately after an BasicProverEnvironment.isUnsat() call that returned false. A model might contain additional symbols with their evaluation, if a solver uses its own temporary symbols. There should be at least an value-assignment for each free symbol.

Specified by:

getModel in interface BasicProverEnvironment<Void>

Throws:

SolverException

getModelAssignments

public ImmutableList<Model.ValueAssignment> getModelAssignments()
                                                         throws SolverException

Description copied from interface: BasicProverEnvironment

Get a list of satisfying assignments. This is equivalent to ImmutableList.copyOf(getModel()), but removes the need for calling Model.close().

Note that if you need to iterate multiple times over the model it may be more efficient to use this method instead of BasicProverEnvironment.getModel() (depending on the solver).

Specified by:

getModelAssignments in interface BasicProverEnvironment<Void>

Throws:

SolverException

toString

public String toString()

Overrides:

toString in class Object

close

public void close()

Description copied from interface: BasicProverEnvironment

Closes the prover environment. The object should be discarded, and should not be used after closing.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface BasicProverEnvironment<Void>